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On the eve of a general election, Henry Collingridge becomes the new leader
of the Conservative Party. His Chief Whip is Francis Urquhart, an icy, intelligent
man who is judged to be reliable but a little old-fashioned. Collingridge
narrowly wins the election but reneges on his promise to promote Urquhart who,
despite his hidden rage, pledges his support.

Urquhart's wife urges him to depose the PM and win the office for himself.
Fuelled by fury and hunger for revenge, the Chief Whip resolves to follow her
suggestion. He begins by manipulating a young journalist named Mattie Storin,
leaking her information that damages Collingridge. Despite the injurious nature
of the material he passes her, Urquhart succeeds in making his intentions appear
honourable, as if he acts solely for the good of his party. He also blackmails
Roger O'Neall, an alcoholic drug abuser who ranks as one of the Conservatives'
top media executives. Urquhart has noted certain financial irregularities in his
expenses claims and exploits this knowledge, forcing O'Neall into lending him
unstinting support.

Urquhart's early maneuverings leave the PM isolated, but a scandal he
concocts concerning Collingridge's brother forces his resignation. Feigning
humility, the Chief Whip announces his intention to stand for the premiership.
He immediately exploits sex scandals, leaks and anonymous threats to discredit
and discourage his opponents, ultimately emerging as the clear favourite to
succeed Collingridge.

However, O'Neall is growing unstable, and Storin, now Urquhart's doting
mistress, begins to suspect she has been a pawn. Before O'Neall can reveal the
truth of the duplicitous plotting, Urquhart laces his supply of cocaine with rat
poison and he dies.

On the verge of becoming Prime Minister, Urquhart waits alone in the House of
Commons' roof gardens, where he is joined by Storin. She confronts him with her
suspicions and, aware she has become a potential liability, he throws her over
the wall to her death. An unseen bystander surreptitiously pockets her dictation
machine which appears to have been recording her final conversation.

En route to Buckingham Palace, where the Queen will invite him to lead her government, the radio broadcasts Urquhart's shallow, distancing eulogy for the woman he murdered.